As is generally known, a programmable thermostat allows a building occupant to set control levels of a building climate-control system, but provides little or no assistance to the building occupant in making decisions on setting them. Typically, a building occupant experiments by trial and error to determine a suitable temperature setting. This process is generally subjective. As a result, the trial and error may yield a nominal solution that does not achieve the efficiency performance entitled by the occupant.
Additionally, once set, a programmable thermostat generally provides a rigid controls schedule that is specified for a given time. For example, a building occupant may set a lower temperature level before going to bed and then raise the level in the subsequent morning in order to maximize his or her comfort and energy efficiency. As such, rather than controlling based on an activity or context, the controls is based on time, which is treated as an approximation to the activity. Thus, any variations as to when the occupant engages in the activity, for example, a different bedtime, may result in a sub-optimal solution.
There is a benefit in having a programmable thermostat that establishes optimally efficient control levels using little or no assistance from the occupant.